1. Field of the Invention
The invention relates to processes and devices for assisting aerial navigation.
2. Discussion of the Background
In general, it is known that in aerodynes (aircraft, helicopters, etc.) of modern design, the pilot must carry out a dialogue with a flight management system, this being a computer on board the aerodyne (we shall subsequently speak of an aircraft) for assisting the pilot in a number of operations. These operations are mainly operations for defining the flight plan before take-off, piloting (manual or automatic) operations during take-off and landing, aerial navigation operations (path calculations, etc.), systematic monitoring operations while cruising or when approaching an airport.
The flight management system operates on the basis of data entered by the pilot, data supplied by sensors distributed throughout the aircraft, and possibly digital data transmitted by radio from the ground or from other aircraft or even satellites.
The dialogue between the flying crew and the flight management system is carried out mainly by means of at least three interfaces, viz.:
a navigation display on which is represented the plot of the desired course of the aircraft, that is to say a graphical representation of the flight plan of the aircraft and the situation of the aircraft within this plan (in two dimensions); PA1 a primary flight display which depicts, on the one hand, an artificial horizon which tilts as the aircraft tilts, and, on the other hand, an indication of the longitudinal attitude of the aircraft, and other useful flying indications; PA1 a flight control unit having manual controls for selecting settings such as the desired heading of the aircraft; PA1 and finally a keyboard/display console, termed the MCDU ("Multipurpose Control Display Unit"), this being a data display and input console allowing the flying crew to enter data into the flight management system and to read information forwarded by the flight management system on the basis of the data entered.
One of the tasks of the pilot consists in calculating, checking and possibly modifying the flight plan of the aircraft, that is to say the essential elements of the course which he is to follow, especially transits above characteristic points called "waypoints".
The flight plan comprises two components: lateral flight plan which defines the waypoints by their longitudes and latitudes, and vertical flight plan which defines the cruising altitudes and the rates of climb and descent during changes of altitude. These elements of the vertical flight plan are defined with respect to the waypoints.
French patent Application 92 03 643 filed on Mar. 26, 1992 proposed a process for assisting pilotage in which the vertical flight plan is displayed separately from the lateral flight plan on a viewing screen, that is to say instead of displaying the vertical flight plan elements in the form of symbolic or textual indications on the lateral flight plan, a vertical flight plan is displayed separately in the form of a plot in a system with two axes, viz. the distances along the abscissa (with indications of the waypoints) and the altitudes along the ordinate.
In such a process, the plot can also comprise a symbol representing the aircraft, which moves with respect to the graduations of the abscissa and of the ordinate as the aircraft advances, and, advantageously, arrangements may even be made for the symbol of the aircraft to remain fixed along the abscissa and for the abscissa scale to scroll along with the advance of the aircraft; thus, it is chiefly that part of the journey still to be made which appears on the screen, and optionally also part of the path that has already been travelled. The symbol of the aircraft can also remain fixed along the ordinate and in this case the altitude scale would scroll as the aircraft climbs or descends.
The vertical flight plan can be depicted on the navigation display and can occupy either the whole of the screen (the pilot then chooses to display either the vertical flight plan or the lateral flight plan) or one part of the screen, the other part being assigned to the lateral flight plan; the pilot can then see the lateral flight plan and the vertical flight plan at the same time.